Fabrication of Carbonate Apatite Block through a Dissolution-Precipitation Reaction Using Calcium Hydrogen Phosphate Dihydrate Block as a Precursor.

Carbonate apatite (CO₃Ap) block, which is a bone replacement used to repair defects, was fabricated through a dissolution-precipitation reaction using a calcium hydrogen phosphate dihydrate (DCPD) block as a precursor. When the DCPD block was immersed in NaHCO₃ or Na₂CO₃ solution at 80 °C, DCPD converted to CO₃Ap within 3 days. β-Tricalcium phosphate was formed as an intermediate phase, and it was completely converted to CO₃Ap within 2 weeks when the DCPD block was immersed in Na₂CO₃ solution.

Evaluation of carbonate apatite blocks fabricated from dicalcium phosphate dihydrate blocks for reconstruction of rabbit femoral and tibial defects.

This study aimed to evaluate in vivo behavior of a carbonate apatite (COAp) block fabricated by compositional transformation via a dissolution-precipitation reaction using a calcium hydrogen phosphate dihydrate [DCPD: CaHPO·2HO] block as a precursor. These blocks were used to reconstruct defects in the femur and tibia of rabbits, using sintered dense hydroxyapatite (HAp) blocks as the control. Both the COAp and HAp blocks showed excellent tissue response and good osteoconductivity.

Late Anterior Dislocation Due to Posterior Pelvic Tilt in Total Hip Arthroplasty.

Background: Excessive pelvic tilt may be one of the factors leading to instability in total hip arthroplasty (THA), even when the acetabular cup is placed properly. To our knowledge, only a few studies have described late anterior dislocation due to posterior pelvic tilt. We present 3 cases with late anterior dislocations possibly due to posterior pelvic tilt.

Quantification of pelvic tilt and rotation by width/height ratio of obturator foramina on anteroposterior radiographs.

Objective: Compared to sagittal pelvic tilt, only a few studies have examined axial rotation on anteroposterior radiographs. We therefore quantified 3-D pelvic rotation using the width and height ratio of the obturator foramina under the various pelvic tilts.

Methods: Using CT reconstructions of 10 healthy pelvises, anterior pelvic planes (APPs) were rotated by 20° in 5° increments on the axial plane with various degrees of sagittal pelvic tilt.

Is a Stem Version on the Crosstable Lateral Radiograph Accurate in Total Hip Arthroplasty?

Background: In contrast to the acetabular cup version (CV), stem version (SV) measurement on the crosstable lateral radiograph has not been validated. We, therefore, investigated: (1) the difference of SV on the crosstable lateral radiograph from that measured using computed tomography data and (2) the reliability of SV measurement on the crosstable lateral radiograph.

Methods: We examined the correlations of the crosstable-CV and crosstable-SV with true-CV (operative cup anteversion) and true-SV (neck version relative to the posterior condylar line) obtained using computed tomography data from 103 patients.

High prevalence of cam deformity in dysplastic hips: A three-dimensional CT study.

Cam deformity could lead to suboptimal articulation by causing secondary femoroacetabular impingement after periacetabular osteotomy; however, the inherent femoral head-neck morphology in dysplastic hips and the effect of an additional osteoarthritic deformity have not been well described. We compared femoral head-neck morphology using three-dimensional imaging of normal and dysplastic hips in pre/early (Tönnis grade 0 and 1) and advanced stage osteoarthritis (Tönnis grade 2). Using computed tomography, we measured the circumferential α-angle and head-neck offset ratio in 68 dysplastic hips and 24 normal hips.

Bone bonding strength of diamond-structured porous titanium-alloy implants manufactured using the electron beam-melting technique.

The present study examined the bone bonding strength of diamond-structured porous titanium-alloy (Porous-Ti-alloy) manufactured using the electron beam-melting technique in comparison with fiber mesh-coated or rough-surfaced implants. Cylindrical implants with four different pore sizes (500, 640, 800, and 1000μm) of Porous-Ti-alloy, titanium fiber mesh (FM), and surfaces roughened by titanium arc spray (Ti-spray) were implanted into the distal femur of rabbits. Bone bonding strength and histological bone ingrowth were evaluated at 4 and 12weeks after implantation.

Pelvic tilt and movement during total hip arthroplasty in the lateral decubitus position.

Objectives: Total hip arthroplasty (THA) is often performed in the lateral decubitus (lateral) position. In this position, the pelvis may have various degrees of tilt leading to implant malposition. We sought to quantify the pelvic tilt in lateral position and further pelvic movement during surgery.

Kinematic analysis of healthy hips during weight-bearing activities by 3D-to-2D model-to-image registration technique.

Dynamic hip kinematics during weight-bearing activities were analyzed for six healthy subjects. Continuous X-ray images of gait, chair-rising, squatting, and twisting were taken using a flat panel X-ray detector. Digitally reconstructed radiographic images were used for 3D-to-2D model-to-image registration technique.

Optimal anterior femoral offset for functional range of motion in total hip arthroplasty--a computer simulation study.

Purpose: Compared to medial femoral offset (MFO), the role of anterior femoral offset (AFO) on range of motion (ROM) in total hip arthroplasty (THA) has not been fully examined. We therefore defined AFO as the anterior distance from the centre of the femoral head to the proximal femoral axis in the sagittal plane and determined the optimal AFO required for ROM needed for activities of daily living using a computer-simulated THA model.

Methods: Various AFOs were obtained by changing stem anteversion (stem-AV) and stem tilt in the sagittal plane (stem-tilt) using a CT-based simulation software.

Clinical and radiographic evaluation of total hip arthroplasties using porous tantalum modular acetabular components: 5-year follow-up of clinical trial.

Objectives: Porous tantalum is a biomaterial newly applied for artificial joints. We present here 5-years follow-up report of a multicenter clinical trial of total hip arthroplasties (THA) with porous tantalum modular acetabular component (modular PTC).

Methods: Study participants received 82 hips in 79 cases, with 61.

Atorvastatin upregulates nitric oxide synthases with Rho-kinase inhibition and Akt activation in the kidney of spontaneously hypertensive rats.

Objective: 3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, statins reduce blood pressure and have beneficial effects in cardiovascular and kidney diseases. The present study examined the effect of chronic treatment with atorvastatin (ATV) on the expression of nitric oxide synthase (NOS) and the activity of Rho-kinase and Akt in the kidney of spontaneously hypertensive rats (SHRs).

Methods: SHRs were treated with ATV for 8 weeks and the SBP was measured.

Effects of estradiol, angiotensin-converting enzyme inhibitor and exercise training on exercise capacity and skeletal muscle in old female rats.

Physical fitness is closely related to cardiovascular health. We examined the effects of estradiol, angiotensin-converting enzyme inhibitor, exercise training, and their combination on exercise capacity as well as skeletal muscle fiber type and capillarity in old female rats. Twelve-month-old female Wistar-Kyoto rats were allocated to six groups: control (C), treatment with 17 beta-estradiol (0.

Combination of chronic exercise and antihypertensive therapy enhances renoprotective effects in rats with renal ablation.

Background: We assessed the renal protective effects of treatment with moderate exercise (EX), with EX plus olmesartan (OLS), with EX plus azelnidipine (AZN), and with the three together in a rat model of chronic renal failure (CRF).

Methods: Male 5/6-nephrectomized Wistar Kyoto (WKY) rats were divided into six groups according to the following treatments for: (i) no EX (C); (ii) moderate EX with treadmill running (20 m/min for 60 min/day, 5 days/week) (EX); (iii) EX+OLS (10 mg/kg/day); (iv) EX+AZN (3 mg/kg/day); (v) EX+OLS (5 mg/kg/day)+AZN (1.5 mg/kg/day); and (vi) sham operation (S).

Increased expression of urotensin II-related peptide and its receptor in kidney with hypertension or renal failure.

Urotensin II-related peptide (URP) is a novel vasoactive peptide that shares urotensin II receptor (UT) with urotensin II. In order to clarify possible changes of URP expression in hypertension and chronic renal failure (CRF), the expressions of URP and UT were studied by quantitative RT-PCR and immunohistochemistry in kidneys obtained from spontaneous hypertensive rats (SHR), Wistar-Kyoto rats (WKY), and WKY with CRF due to 5/6 nephrectomy. Expression levels of URP mRNA and UT mRNA were significantly higher in the kidneys obtained from SHR compared with age-matched WKY (at 5-16 and 16 weeks old, respectively).

Effects of antihypertensive drugs and exercise training on insulin sensitivity in spontaneously hypertensive rats.

We examined the effects of antihypertensive drugs, exercise training, and combinations thereof on insulin sensitivity (IS), and the association between this relation and sympathetic activity, muscle fiber composition, and capillary density in spontaneously hypertensive rats (SHR). Six-week-old male SHR were allocated to 7 groups: a control group (C), and groups treated with azelnidipine (Aze) (a calcium channel blocker), olmesartan (Olm) (an angiotensin II type 1 receptor blocker), exercise training (Exe), and combinations of drugs and exercise training (Aze+Exe, Olm+Exe, and Olm+Aze+Exe). At age 18 weeks, IS and sympathetic activity were evaluated by an euglycemic hyperinsulinemic glucose clamp technique and power spectral analysis of systolic blood pressure, respectively.

Combination of exercise and losartan enhances renoprotective and peripheral effects in spontaneously type 2 diabetes mellitus rats with nephropathy.

Objectives: We assessed the renal and peripheral effects of chronic exercise in a rat model of diabetic nephropathy and the benefits of combined exercise and losartan.

Methods: Heminephrectomized Goto-Kakizaki rats were divided into four groups: (i) no exercise (control); (ii) exercise with treadmill running; (iii) losartan; (iv) exercise plus losartan, and the rats were treated for 12 weeks.

Results: Losartan and exercise plus losartan significantly decreased systolic blood pressure (SBP).

Effects of angiotensin-converting enzyme inhibitor and exercise training on exercise capacity and skeletal muscle.

Objective: Physical fitness is closely related with cardiovascular health. We examined the effects of angiotensin-converting enzyme inhibitor, exercise training and their combination on exercise capacity as well as skeletal muscle fiber type and capillarity in spontaneously hypertensive rats (SHR).

Methods: Seven-week-old male SHR were allocated to four groups: sedentary control (C), treatment with perindopril (3 mg/kg per day) (Per), exercise training on a treadmill (EX), and their combination (Per + EX).

Exercise training fails to modify arterial baroreflex sensitivity in ovariectomized female rats.

In men, exercise training attenuates age-related reduction in baroreflex sensitivity, which is related to cardiovascular health. It is unknown, however, if this holds true for post-menopausal women. We examined the effects of exercise training on baroreceptor-heart rate (HR) reflex sensitivity in ovariectomized (OVX) and sham-operated (SO) Wistar-Kyoto rats.

Mechanism behind augmentation in baroreflex sensitivity after acute exercise in spontaneously hypertensive rats.

A single bout of dynamic exercise increases baroreflex sensitivity (BRS) in spontaneously hypertensive rats (SHR). We examined whether change in hemodynamics (increases in blood pressure and heart rate) associated with dynamic exercise contribute to the post-exercise modulation of BRS. SHR aged 12 weeks were chronically instrumented with a carotid artery catheter and jugular vein catheter.

Expression of cytochrome P-450 4 enzymes in the kidney and liver: regulation by PPAR and species-difference between rat and human.

Members of the cytochrome P-450 4 (CYP4) family catalyze the omega-hydroxylation of fatty acids, and some of them have the PPAR response element in the promoter area of the genes. The localization of CYP4A and PPAR isoforms and the effect of PPAR agonists on CYP4A protein level and activity were determined in rat kidney and liver. Immunoblot analysis showed that CYP4A was expressed in the liver and proximal tubule, with lower expression in the preglomerular microvessel, glomerulus and thick ascending limb (TAL), but the expression was not detected in the collecting duct.

[Renoprotective and antihypertensive effect of combination therapy with a low protein diet, long-term exercise and angiotensin II receptor antagonist in rats with renal ablation].

A low protein diet(LPD) has been prescribed to alleviate uremic symptoms, and to delay the aggravation of chronic renal failure(CRF). However, it has been suggested that LPD treatment causes malnutrition and attenuation of muscle power. On the other hand, it also has been suggested that appropriate long-term exercise training(EX) may lead to improvement of the physical fitness and quality of life (QOL) in patients with CRF.

Combination of exercise and enalapril enhances renoprotective and peripheral effects in rats with renal ablation.

Background: It is suggested that appropriate chronic exercise (EX) may produce improvements of the physical strength in patients with chronic renal failure (CRF). Because acute exercise causes proteinuria and decreases the renal blood flow and glomerular filtration rate, it is necessary to consider the influence of EX on renal function. Therefore, we assessed the renal and peripheral effects of moderate to intense EX as well as the effects of the combination of EX and enalapril (ENA) in a rat model of CRF.

Renoprotective effect of angiotensin-converting enzyme inhibitor combined with alpha1-adrenergic antagonist in spontaneously hypertensive rats with renal ablation.

To assess the renal benefits of combined angiotensin-converting enzyme inhibition and alpha(1)-adrenergic antagonism, we studied the antihypertensive and renoprotective effects of temocapril (TMP) alone and in combination with doxazosin (DOX) in spontaneously hypertensive rats (SHR)/Izumo rats with renal ablation. Five-Sixths-nephrectomized rats were assigned to receive TMP (10 mg/kg/day) (TMP group), TMP plus DOX (2 mg/kg/day) (TMP+DOX group), or vehicle (control group) orally for 12 weeks. Both systolic blood pressure (SBP) and urinary excretion of albumin (UalbV) in the control group progressively increased during the experimental period and were significantly higher than in sham-operated rats.